Lesson 3 — The Twelve Signs

The twelve signs form the foundation for understanding how planets express their nature in a horoscope

Learn how the twelve zodiac signs shape the expression of the planets in traditional natal astrology, using sign classifications, rulers, and practical examples

Gemini: The Twins

Sidney Hall’s (1831) astronomical chart illustration of the zodiac Gemini.

Mentally agile and curious, the mutable, Mercury-ruled air sign of Gemini gathers information, synthesizes, and reports. But at its mythological roots, this sign’s capacity to be two things at once reveals the unifying power of companionship.